An SPR (Surface Plasmon Resonance) technique may be used for kinetic parameter measurement of molecular identification, specific reaction and inter-molecular reaction and the like, and has wide application. A spectrum diagnosis SPR technique has a large dynamic range, high sensitivity and involved mature photoelectric equipment, and therefore is broadly researched by domestic and foreign scholars. However, positions of SPR resonance wavelengths cannot be directly and correctly measured. Since corresponding intensity may be equal to zero in theory, region values near zero are basically submerged in noise, and the sensitivity of the SPR technique is extremely sensitive to spectrum resolution capability, the resolution capability of the spectrum position is generally required to reach 0.01 nm. Moreover, with inter-molecular dynamic interaction of a sensing surface, resonance wavelengths will move, a movement magnitude is correlated to concentration of reaction molecules and molecular weights. For an ordinary protein molecule such as IgG, the concentration is 5 ug/ml, the movement range is about 2-3 nm, and reaction time is about 5 minutes. In order to measure a curve of a resonance wavelength varying with reaction time, namely, an SPR spectrum curve, time resolution is generally required to be less than 1 second. Specifically, it is generally required to perform parallel high-flux measurement on the whole two-dimensional sensing surface in fact Since the difference between different positions of the sensing surface may lead different resonance wavelengths of various sites, and therefore how to rapidly diagnose SPR resonance wavelengths of various sites of the whole sensing chip within 1 second is a bottleneck of a spectrum diagnosis SPR technique.
At present, there are two SPR diagnosis methods One method is that high-flux measurement is obtained by sacrificing time; the other method is that high time resolution is obtained by sacrificing measurement flux. The former adopts a monochrometer to scan a wavelength of an incident light and synchronously records light intensity under each wavelength utilizing a two-dimensional detector such as a CCD camera, a series of intensity images are recorded with the scanning of the incident wavelength, different times correspond to different wavelengths, each image corresponds to one wavelength, a corresponding pixel of each image forms a curve of intensity varying with a spectrum, namely, an SPR spectrum outline curve of points on the corresponding sensing surface, analogically, a series of SPR spectrum outline curves are composed of all the pixels according to the above manner, each curve corresponds to one pixel point of the SPR sensing surface, a minimum value of each SPR spectrum outline line is a resonance light wavelength of this pixel point, the change of a refractive index of a sensor surface is obtained by continuously and repeatedly obtaining the above series of SPR spectrum outline curves within the same fixed spectrum range and monitoring the change of the minimum value of each SPR spectrum outline line, so as to achieve SPR sensing measurement. Beam splitting in the monochrometer is achieved by mainly adopting rotary grating, and rapid cyclical scanning cannot be performed due to factors such as a mechanical scanning manner and rotation element inertia; moreover, due to different sensing film thickness and light incident angles (caused by poor white light source collimation, prism dispersion and the like) and inconsistent resonance spectrum of various points of a sensing chip caused by factors such as types and concentrations of probe molecules as well as inconsistent movement generated by inter-molecular interaction, the whole sensing surface cannot be properly set in advance, and therefore, at present, all the reports are that full-spectrum line scanning is performed in a fixed whole working spectrum segment to avoid some resonance wavelengths to be removed out of the scanning range in the process of measurement to generate measurement error. At presents it is reported that the rapidest scanning speed for the spectrum diagnosis SPR is 2 s/wavelength, and thus time for obtaining the whole SPR spectrum outline once is considerably long, and cannot meet dynamic monitoring of inter-molecular interaction.
The later utilizes a spectrometer to perform rapid spectrum analysis of the reflected light and has a sufficiently rapid measurement speed. In order to improve measurement flux, reflected lights at different positions of a sensing film are respectively guided into different spectrometers to achieve parallel detection, but, each position needs one spectrometer, so cost is expensive, and monitoring and imaging detection of a high-density sensing chip cannot be achieved.
In summary, the existing technology has the following technical problems there is no technology to achieve parallel rapid scanning of SPR spectrum curves of all the sites of a two-dimensional sensing chip, the SPR spectrum curves of all the sites of the two-dimensional sensing chip cannot be rapidly obtained, and then rapid parallel monitoring of resonance wavelengths of all the sites of the two-dimensional sensing chip cannot be achieved, and the existing technology also has defects that the consistence of sensing sensitivities of various position points of the two-dimensional sensing chip is poor.